Railway signaling apparatus



Dec. 29, 1925" 1,567,801

R. M. GILSON RAILWAY S IGNALING APPARATUS Filed June 29, 1925 w;INVENTOR aka-waif M a. ATTORNEY Patented Dec. 29, 1925.

' UNITED STATES:

1,567,801 PATENT OFFICE.

ROBERT M. GILSON, OI PITTSBURGE; PENNSYLVANIA, ASSIGNOR- TO THE UNIONSWITCH 8; SIGNAL COMPANY, OF SWISSVAL'E, PENNSYLVANIA, A' CORPORATION OFPENNSYLVANIA.

RAILWAY SIGNALING ArrARATU-s.

Application filed June29, 1925. Serial No. 40,255.

To aZZ whom it may concern: v

Be it known that I, Roenn'r M. GiLsoN, a citizen of the United States,residing at Pittsburgh, in the county of Allegheny and StateofPennsy-lvania, have invented certain new and useful Improvements inRailway Signaling Apparatus, of which the following is a specification.

My invention relates to railway signaling ap ar-atus.

no object of my invention is the promsion, in railway signalingapparatus of the type comprising trackway signals eachnormal'lycontrolled by energy received from a main source, of means for at timessupplying energy to each such signal from an auxiliary source should themain source become ineffective to supply current to the signal.

I will describe one form of railway signaling apparatus embodying myinvention, and willthen point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view illustrating one formofrailway signaling apparatus embodying my invention.

Referring-to the drawing, the reference characters'l and 1? designatethe track rails of a stretch of railway track over which trafficnormally moves in the direction indicated by the arrow. These'trackrails are divided, by means of insulated joints 2, into a plurality ofsuccessive track sections, AB, B-O, etc.

Each track section is provided with a track relay designated by thereference char acter R with an appropriate distinguishing exponent andconnected across the rails adjacent the entrance end of thecorresponding section. Each track section is also pro-' vided with asource of track circuit current, such as a track battery, designated bythe reference character H with a suitable ex-' ponent. Associated witheach track battery is an'auxi'liary relay, here designated by thereference character K with anappropriate.

exponent. Each track battery H. is connected in series with theassociated auxiliary relay K across the rails adjacent the exit end ofthe corresponding section. A 'limiting impedance 6 is insertedin'seriesin each traek'battery H in accordance with the usual practice.each track section is provided with a track It will therefore be plainthat rent supplied by battery H is sufiicient to.

energize the track relay R but is not sufficient to energize theauxiliary relay K. When a train-enters the section, however, the

track relay R isshunted by the wheels and axles of the train andthat'relay becomes deenergized. The shunting effect of the train alsoincreases the current supplied to the rails by battery H and thisincreased current is sufficient to energize the auxiliary relay K. Whenthe train moves'out of the section the track relay again-becomesenergized and the decreased current through relay K allows that relay tobecome de-energized.

Each track section is also provided with a trackway signal designated bythe reference character S with an appropriate distinguishing exponent.As here shown each signal is located adjacent the entrance end of thecorresponding section and comprises two light units 26 and 27 arrangedwhen energized to indicate proceed and stop, respectively, but thisparticular location and arrangement of signals is not essential to myinvention.

Under normal conditions each signal S is controlled by. alternatingcurrent supplied thereto from an associated line transformer designatedby the reference character T with an exponent corresponding to thelocation." The primary 5 of each such line transformer T is constantlysupplied with alternating current from some suitable 'for thiscontingency each track section is equipped with an auxlliary source ofcurrent here shown as a battery designated by the reference character Gwith an exponent corresponding to the location.

Associatedwith each track relay R is a relay which for purpose ofexplanation I will term a power selecting relay, and which is heredesignated by the reference character D with an exponent correspondingto the location.

Referring particularly to relay D this relay is provided with a circuitwhich passes from secondary 4 of transformer T through wires 7 and 8,winding of relay D wire 9, front contact 10 of auxiliary relay K andwires 11 and 12 back to transformer T This circuit is closed only whenrelay K is energized, and it follows that relay D is normallyde-energized but is arranged to become energized when a train enterssection A-B, provided transformer T is supplying current to the circuitjust traced.

Signal S is provided with a proceed circuit which may be traced fromsecondary 4c of transformer T through wires 7 and 18, front contact 14:of relay D wire 15, front contact 16 of relay R wire 17, proceed unit 26of signal S wire 18, front contact 19 of relay K wire 20, front contact21 of relay D and wires 22 and 12 back to transformer T This circuit isclosed only when relays R K and D are all energized. The stop circuitfor signal S may be traced from secondary 4 of transformer T throughwires 7 and 18, front contact 14 of relay D wire 15, back contact 16 ofrelay R wire 23, stop unit 27 of signal S wire 18, front contact 19 ofrelay K wire 20, front contact 21 of relay D and wires 22 and 12 back totransformer T This circuit is closed only when relays K and D are bothenergized, and relay B is de-energized. It will be plain from theforegoing that both the proceed circuit and the stop circuit for signalS include front contact 19 of relay K so that both units of this signalare normally extinguished. If, however, relay K is energized, as by thepresence of a train in section AB, and if power selecting relay D isalso energized, signal S will display a proceed indication or a stopindication according as track relay R is energized or de-energized,respectively. I will assume, however, that relay K is energized as bythe presence of a train in section A-A, and that the supply ofalternating current from transformer T is, for some reason, interrupted.Relay D will then be de-energized and its back contacts 21 and 14 willbe closed. As a result battery G is connected across wires and so thatcurrent is supplied by this battery to the proceed unit 26 or the stopunit 27 of signal S according as relay B is energized or de-energized.It will be plain therefore that when a train is approaching signal Scurrent will be supplied to one or the other of the light units of thesignal 5, depending upon trafiic conditions in section BC. It will alsobe plain that under normal conditions this current will be supplied fromtransformer T, but that should the supply of current from thistransformer be interrupted, the consequent de-energization of relay Dwill connect battery G with the signal.

As shown in the drawing the section to the right of point C is occupiedby a train indicated diagrammatically at V, and sections A-B and BC areunoccupied. Relay R is therefore tie-energized. Relay B is energized andrelay K is de-energized. Relay D is de-energized, its circuit being openat front contact 10 of relay K Both circuits for signal S are open atfront contact 19 of relay K and so neither unit of signal S is lighted.Similarly, relays K and D are de-energized and both units of signal Sare extinguished. It will also be clear from the drawing that relay R isenergized; relays K and D are Clo-energized and neither unit of signal Sis lighted.

I will now assume that a train moving in the direction of the arrowenters section A-B. The shunting effect of this train causes relay K tobecome energized. Relay D therefore becomes energized, and since relay Ris picked up, current is supplied to proceed unit 26 of signal S fromtransformer T so that signal S indicates proceed. If, however, thesupply of current from transformer T should be interrupted this wouldhave no effect upon relays K and R but relay D would becomede-energized. Current would then be supplied from battery G to proceedunit 26 of signal S over the back contacts of relay D front contact 19of relay K and front contact 16 of relay R As the train enters sectionBG relay R becomes de-energized thereby completing the circuit for stopunit 27 of signal S and this signal indicates stop. The entrance of thetrain into section BC also causes relay K to pick up. Current fromtransformer T therefore energizes relay D Back contact 16 of relay R isclosed, and current from transformer T therefore energizes stop unit 27of signal S so that signal S indicates stop. Should the supply ofcurrent from transformer T be interrupted the resulting de-energizationof relay ID would connect battery G with the signal S so that currentfrom battery G would then energize unit 27 of signal S to indicate stop.When the train moves out of section AB relay K becomes de-energized. Theilluminated unit of signal S is therefore eXtingu'ished. When the trainmoves out of section-BC the energization of relay R and thede-energization of relay D restore the apparatus to its normal conditionand ex tinguish the illuminated unit of signal S With apparatusembodying my invention,

therefore, it will be manifest that when a train enters a section, thesi nal for the sec tion next in advance is supp ied with energy from theassociated line transformer. If, however, the supply of energy from thetransformer associated with such signal fails, the adjacent relay Dopens and supplies energy to the signal from the corresponding batteryG.

Although I have herein shown and described only one form of railwaysignaling apparatus embodying my invention, it is understood thatvarious changes and 1nodifications may be made therein within the scopeof the appended claims without departing from the spirit and scope of myinvention. 7

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track, a signal for saidstretch, a main source of current, a relay, means effective when a trainapproaches said section for supplying current from said main source tosaid relay, means for supplying current from said main source to saidsignal when said relay is energized, an auxiliary source of current, andmeans for supplying current to said signal from said auxiliary sourcewhen a train approaches said section if said relay is de-energized.

2. In combination, a stretch of railway track, a signal for saidstretch, a main source of current, a relay, means effective only when atrain is approaching said signal for energizing said relay from saidsource, an auxiliary source of current, and means effective when a trainis approaching said signal for supplying current to said signal fromsaid main source or from said auxiliary source according as said relayis energized or de-energized.

3. In combination, a stretch of railway track, a signal for saidstretch, a main source of current, an auxiliary source of current, andmeans for supplying current from said main source to said signal but forsupplying current to said signal from said auxiliary source should saidmain source fail, said means being effective only when a train isapproaching said signal. 7

4:. In combination, a stretch of railway track, a signal for saidstretch, a main source of current, an auxiliary source of current, andmeans responsive to current from said main source and effective onlywhen a train is approaching said signal for selec tively connecting saidsignal with said main source or with said auxiliary source.

5. In combination, a stretch of railway track, a signal for saidstretch, a main source of current, an auxiliary source of current, acontact arranged to be operated when a train approaches said signal, andmeans controlled by said contact and responsive to current from saidmain source for selectively connecting said signal with said main sourceor with said auxiliary source.

6. In combination, a stretch of railway track, a signal for saidstretch, a main source of current, an auxiliary source of current, twonormally open contacts arranged to be closed when a train approachessaid signal, a relay, means effective when one of said contacts isclosed for supplying current to said relay from said main source, andmeans effective when said other contact is closed for connecting saidsignal with said main source or with said auxiliary source according assaid relay is energized or de-energized, respectively.

7. In combination, a forward and a rear section of railway track, asignal for said forward section, an auxiliary relay for said rearsection arranged to be energized when said section is occupied by atrain, a main source of current, an auxiliary source of current, a powerselecting relay, a circuit for said power selecting relay including saidmain source and a front contact of said auxiliary relay; a first circuitfor said signal including said main source, a front contact of saidpower selecting relay, and a front contact of said auxiliary relay; anda second circuit for said signal including said auxiliary source, a backcontact of said power selecting relay, and a front contact of saidauxiliary relay.

In testimony whereof I aflix my signature.

ROBERT M. GILSON.

